Unique Glow Helps Identify Two New Fish Species

Scientists have found two new species of glowing fish with tube-shaped eyes and mirrors on their bellies, according to their research in journal PLOS One.

The Opisthoproctidae, or barreleyes, are a unusual family. For example, take a look at the transparent-headed, tiny-mouthed Macropinna microstoma. Those green objects pointing upward are its eyes, and what appear to be eyes at front are actually the barreleye equivalent of nostrils.

Scientists have had a hard time getting to know the barreleyes better because the fishes’ delicate bodies kind of collapse once they’re out of the water. M. microstoma, for example, was first described in 1939, but nobody knew about its clear, fragile forehead until a remotely operated vehicle captured the video above in 2004.

Based on the evidence they had, researchers believed there were 19 species in the barreleye family. Some of these species have bioluminescent, or light-producing, organs in their bellies, along with mirror-like organs called soles that lie beneath the glow, controlling and directing its light.

During a research cruise in 2013 and 2014, the Japanese research vessel Hakuho-Maru pulled up four fish that looked like barreleyes. Researchers onboard the boat took tissue samples, then dropped the fish into ethanol and stored them in a sub-zero freezer to help the specimens keep their shape.

An international team of scientists took it from there. They examined and photographed the specimens and sequenced their DNA, then compared these results with data on existing barreleye species. They found that, while similar to one another, the new fishes’ mirror bellies showed three different types of markings. The DNA tests confirmed it: They were three different species, two of which had never been seen before. The new species were definitely barreleyes, but were so distinct from known species that the researchers put them in a separate genus, Monacoa. (They suggest calling them "long-nosed mirrorbellies" in the vernacular.)

Monacoa is what’s called a resurrected genus. A long time ago, ichthyologist GP Whitley believed he’d found a fish different enough from its kin to merit a new genus, which he named Monacoa. Later, other scientists disagreed, and moved Monacoa grimaldii into the genus Opisthoproctus. But based on the markings on the new fishes’ bellies, the authors of the current study say Whitley was right. They realized that the old specimens could never have led to this conclusion, as the formalin used to preserve the fish damaged their markings.

The two new species, M. niger and M. griseus, are both native to the Pacific Ocean. Unlike other fish that prefer pure blackness, these fish inhabit depths that still get some sunlight. In semi-lit conditions, the authors say, the barreleyes might use their bioluminescence as camouflage, or to communicate with one another.

"This new study on the deep-sea has shown unknown biodiversity in a group of fishes previously considered teratological variations of other species," lead author Jan Poulsen of the Australian Museum said in a press statement. "The different species of mirrorbelly-tube eyes can only be distinguished on pigmentation patterns that also constitutes a newly discovered communication system in deep-sea fishes."

Hedgehogs as pets have gained popularity in recent years, but in many parts of the world, they're still wild animals. That includes London, where close to a million of the creatures roam streets, parks, and gardens, seeking out wood and vegetation to take refuge in. Now, Atlas Obscura reports that animal activists are transforming the city into a more hospitable environment for hedgehogs.

Barnes Hedgehogs, a group founded by Michel Birkenwald in the London neighborhood of Barnes four years ago, is responsible for drilling tiny "hedgehog highways" through walls around London. The passages are just wide enough for the animals to climb through, making it easier for them to travel from one green space to the next.

London's wild hedgehog population has seen a sharp decline in recent decades. Though it's hard to pin down accurate numbers for the elusive animals, surveys have shown that the British population has dwindled by tens of millions since the 1950s. This is due to factors like human development and habitat destruction by farmers who aren't fond of the unattractive shrubs, hedges, and dead wood that hedgehogs use as their homes.

When such environments are left to grow, they can still be hard for hedgehogs to access. Carving hedgehog highways through the stone partitions and wooden fences bordering parks and gardens is one way Barnes Hedgehogs is making life in the big city a little easier for its most prickly residents.

Soon, the dogs you see sniffing out contraband at airports may not be searching for drugs or smuggled Spanish ham. They might be looking for stolen treasures.

K-9 Artifact Finders, a new collaboration between New Hampshire-based cultural heritage law firm Red Arch and the University of Pennsylvania, is training dogs to root out stolen antiquities looted from archaeological sites and museums. The dogs would be stopping them at borders before the items can be sold elsewhere on the black market.

The illegal antiquities trade nets more than $3 billion per year around the world, and trafficking hits countries dealing with ongoing conflict, like Syria and Iraq today, particularly hard. By one estimate, around half a million artifacts were stolen from museums and archaeological sites throughout Iraq between 2003 and 2005 alone. (Famously, the craft-supply chain Hobby Lobby was fined $3 million in 2017 for buying thousands of ancient artifacts looted from Iraq.) In Syria, the Islamic State has been known to loot and sell ancient artifacts including statues, jewelry, and art to fund its operations.

But the problem spans across the world. Between 2007 and 2016, U.S. Customs and Border Control discovered more than 7800 cultural artifacts in the U.S. looted from 30 different countries.

Penn Vet Working Dog Center

K-9 Artifact Finders is the brainchild of Rick St. Hilaire, the executive director of Red Arch. His non-profit firm researches cultural heritage property law and preservation policy, including studying archaeological site looting and antiquities trafficking. Back in 2015, St. Hilaire was reading an article about a working dog trained to sniff out electronics that was able to find USB drives, SD cards, and other data storage devices. He wondered, if dogs could be trained to identify the scents of inorganic materials that make up electronics, could they be trained to sniff out ancient pottery?

To find out, St. Hilaire tells Mental Floss, he contacted the Penn Vet Working Dog Center, a research and training center for detection dogs. In December 2017, Red Arch, the Working Dog Center, and the Penn Museum (which is providing the artifacts to train the dogs) launched K-9 Artifact Finders, and in late January 2018, the five dogs selected for the project began their training, starting with learning the distinct smell of ancient pottery.

“Our theory is, it is a porous material that’s going to have a lot more odor than, say, a metal,” says Cindy Otto, the executive director of the Penn Vet Working Dog Center and the project’s principal investigator.

As you might imagine, museum curators may not be keen on exposing fragile ancient materials to four Labrador retrievers and a German shepherd, and the Working Dog Center didn’t want to take any risks with the Penn Museum’s priceless artifacts. So instead of letting the dogs have free rein to sniff the materials themselves, the project is using cotton balls. The researchers seal the artifacts (broken shards of Syrian pottery) in airtight bags with a cotton ball for 72 hours, then ask the dogs to find the cotton balls in the lab. They’re being trained to disregard the smell of the cotton ball itself, the smell of the bag it was stored in, and ideally, the smell of modern-day pottery, eventually being able to zero in on the smell that distinguishes ancient pottery specifically.

Penn Vet Working Dog Center

“The dogs are responding well,” Otto tells Mental Floss, explaining that the training program is at the stage of "exposing them to the odor and having them recognize it.”

The dogs involved in the project were chosen for their calm-but-curious demeanors and sensitive noses (one also works as a drug-detection dog when she’s not training on pottery). They had to be motivated enough to want to hunt down the cotton balls, but not aggressive or easily distracted.

Right now, the dogs train three days a week, and will continue to work on their pottery-detection skills for the first stage of the project, which the researchers expect will last for the next nine months. Depending on how the first phase of the training goes, the researchers hope to be able to then take the dogs out into the field to see if they can find the odor of ancient pottery in real-life situations, like in suitcases, rather than in a laboratory setting. Eventually, they also hope to train the dogs on other types of objects, and perhaps even pinpoint the chemical signatures that make artifacts smell distinct.

Pottery-sniffing dogs won’t be showing up at airport customs or on shipping docks soon, but one day, they could be as common as drug-sniffing canines. If dogs can detect low blood sugar or find a tiny USB drive hidden in a house, surely they can figure out if you’re smuggling a sculpture made thousands of years ago in your suitcase.